EP-A 182 333 discloses that highly dilute cycloolefin solutions can be converted by a metathesis reaction in the liquid phase using the catalyst system Re2O7/γ-Al2O3/SnR4, where R is an alkyl radical, into the corresponding cycloalkadienes.
The preparation of cycloalkadienes by a metathesis reaction of cyclooctenylenes having a degree of polymerization of greater than or equal to three and/or cycloalkamonoenes in the liquid phase in the presence of a supported catalyst based on Re2O7/γ-Al2O3 is described in EP-A 343 437.
Chemiker-Zeitung 1983, 107, 115, describes the preparation of cycloalkadienes over a Re2O7/γ-Al2O3 catalyst. As support material, use was made of γ-Al2O3-CK-300 from Akzo.
EP-B 991 467 describes Re2O7/γ-Al2O3 catalysts containing boron oxide and having the form of extrudates.
Due to the necessarily high dilution of the cycloolefin solutions used in the metathesis reaction, the amount of cycloalkadienes, which is obtainable per unit time, has been unsatisfactory from economic, engineering and industrial points of view.